Control of atomic entanglement by dynamic Stark effect

TL;DR

This paper investigates how the dynamic Stark effect can be used to control and enhance entanglement between two three-level Rydberg atoms passing through a cavity, demonstrating methods to sustain entanglement despite detuning.

Contribution

It introduces an effective Hamiltonian incorporating Stark shifts to manipulate atomic entanglement, showing how Stark tuning can optimize entanglement in cavity QED systems.

Findings

Stark shift can enhance atomic entanglement compared to resonant conditions.

Entanglement diminishes with increased two-photon detuning and Stark shift.

Proper compensation of detuning and Stark shift can sustain entanglement over time.

Abstract

We study the entanglement properties of two three-level Rydberg atoms passing through a single-mode cavity. The interaction of an atom with the cavity field allows the atom to make a transition from the upper most (lower most) to the lower most (upper most) level by emission (absoprtion) of two photons via the middle level. We employ an effective Hamiltonian that describes the system with a Stark shifted two-photon atomic transition. We compute the entanglement of formation of the joint two-atom state as a function of Rabi angle $gt$. It is shown that the Stark shift can be used to enhance the magnitude of atomic entanglement over that obtained in the resonant condition for certain parameter values. We find that though the two-atom entanglement generally diminishes with the increase of the two-photon detuning and the Stark shift, it is possible to sustain the entanglement over a range of interaction times by making the detuning and the Stark shift compensate each other. Similar characteristics are obtained for a thermal state cavity field too.